Method and apparatus for controlling transmission power in wireless communication system

ABSTRACT

Provided is a method and apparatus for controlling transmission power in a wireless communication system. A terminal sets transmission power of a physical uplink control channel (PUCCH). Among a plurality of physical uplink shared channels (PUSCHs), at least one PUSCH to which uplink control information (UCI) is not mapped is decreased in transmission power based on a maximum transmission power of the terminal and the transmission power of the PUCCH, and transmission power of at least one second PUSCH, of the plurality of PUSCHs to which UCI is mapped, is set. At this time, the UCI and uplink data are transmitted through the PUCCH, the at least one first PUSCH, and the at least one second PUSCH; and the at least one first PUSCH and the at least one second PUSCH are allocated to component carriers (CCs) of a plurality of uplinks (ULs).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to wireless communication, and moreparticularly, to a method and apparatus for controlling transmissionpower in a wireless communication system.

2. Related Art

Effective transmission/reception methods and utilizations have beenproposed for a broadband wireless communication system to maximizeefficiency of radio resources. An orthogonal frequency divisionmultiplexing (OFDM) system capable of reducing inter-symbol interference(ISI) with a low complexity is taken into consideration as one of nextgeneration wireless communication systems. In the OFDM, a serially inputdata symbol is converted into N parallel data symbols, and is thentransmitted by being carried on each of separated N subcarriers. Thesubcarriers maintain orthogonality in a frequency dimension. Eachorthogonal channel experiences mutually independent frequency selectivefading, and an interval of a transmitted symbol is increased, therebyminimizing inter-symbol interference.

When a system uses the OFDM as a modulation scheme, orthogonal frequencydivision multiple access (OFDMA) is a multiple access scheme in whichmultiple access is achieved by independently providing some of availablesubcarriers to a plurality of users. In the OFDMA, frequency resources(i.e., subcarriers) are provided to the respective users, and therespective frequency resources do not overlap with one another ingeneral since they are independently provided to the plurality of users.Consequently, the frequency resources are allocated to the respectiveusers in a mutually exclusive manner. In an OFDMA system, frequencydiversity for multiple users can be obtained by using frequencyselective scheduling, and subcarriers can be allocated variouslyaccording to a permutation rule for the subcarriers. In addition, aspatial multiplexing scheme using multiple antennas can be used toincrease efficiency of a spatial domain.

An uplink control information (UCI) can be transmitted through an uplinkcontrol channel, i.e., a physical uplink control channel (PUCCH). TheUCI may include various types of information such as a schedulingrequest (SR), an acknowledgement/non-acknowledgement (ACK/NACK) for ahybrid automatic repeat request (HARQ), a channel quality indicator(CQI), a precoding matrix indicator (PMI), a rank indicator (RI), etc.The PUCCH carries various types of control information according to aformat. Transmission of the UCI through the PUCCH may be found in thesection 10 of 3^(rd) generation partnership project (3GPP) TS 36.213V8.8.0 (2009-09).

Meanwhile, a carrier aggregation (CA) system implies a system whichsupports a broadband by aggregating one or more carriers having abandwidth narrower than that of a desired broadband when a wirelesscommunication system intends to support the broadband. In the CA system,a user equipment can simultaneously transmit or receive one or aplurality of carriers according to capacity. The conventionaltransmission technique can be newly defined in the CA system. The CAsystem may be found in 3GPP TR 36.815 V9.0.0 (2010-3).

In a carrier aggregation system, a user equipment (UE) can periodicallytransmit the UCI through a plurality of component carriers (CCs), or canaperiodically transmit the CQI. In this case, maximum transmission powerof the UE can be limited, and the UE can allocate and/or control powerfor each UL transmission channel, i.e., a PUCCH and a physical uplinkshared channel (PUSCH).

There is a need for a method for properly allocating power for each ULchannel.

SUMMARY OF THE INVENTION

The present invention provides a method and apparatus for controllingtransmission power in a wireless communication system. The presentinvention provides a method and apparatus for controlling transmissionpower of each uplink channel when periodic uplink control information(UCI) and aperiodic channel quality indicator (CQI) are transmittedthrough a plurality of component carriers (CCs).

In an aspect, a method of controlling transmission power by a terminalin a wireless communication system is provided. The method includesdetermining transmission power of a physical uplink control channel(PUCCH), determining transmission power of at least one first uplinkshared channel (PUSCH) to which an uplink control information (UCI) isnot mapped by scaling down the transmission power thereof among aplurality of PUSCHs on the basis of maximum transmission power of theterminal and the transmission power of the PUCCH, determiningtransmission power of at least one second PUSCH to which the UCI ismapped among the plurality of PUSCHs, and transmitting the UCI anduplink (UL) data through the PUCCH, the at least one first PUSCH, andthe at least one second PUSCH. The at least one first PUSCH and the atleast one second PUSCH are allocated to a plurality of UL componentcarriers (CCs).

The transmission power of the at least one first PUSCH may be determinedby being scaled down to satisfy the equation of

${{\sum\limits_{c}{w_{c} \cdot {P_{PUSCHc}(i)}}} \leq {P_{CMAX} - {P_{PUCCH}(i)}}},$

where w_(c) is a scaling factor for scaling down the transmission powerof the at least one first PUSCH, c is an index of a UL CC, P_(PUSCHC)(i)is the transmission power of the at least one first PUSCH, P_(CMAX) isthe maximum transmission power of the terminal, and P_(PUCCH)(i) is thetransmission power of the PUCCH.

The UCI may be any one of a periodic UCI, an aperiodic channel qualityindicator (CQI), and a jointly encoded periodic UCI and aperiodic CQI.

The transmission power of the at least one second PUSCH may be evenlydistributed to the at least one second PUSCH.

The transmission power of the at least one second PUSCH may be allocatedto the at least one second PUSCH on the basis of a pre-set priority.

The transmission power of the second PUSCH allocated to a UL primary CC(PCC) may be preferentially allocated among the at least one secondPUSCH.

The priority may be set explicitly by physical downlink control channel(PDCCH) signaling or radio resource control (RRC) signaling.

The priority may be set implicitly on the basis of a size of atransmission block (TB) or an index of a plurality of UL CCs to whichthe at least one second PUSCH is allocated.

The transmission power of the second PUSCH to which an aperiodic CQI maybe mapped is preferentially allocated among the at least one secondPUSCH.

In another aspect, a terminal in a wireless communication system isprovided. The terminal includes a radio frequency (RF) unit fortransmitting or receiving a radio signal, and a processor coupled to theRF unit. The processor is configured for determining transmission powerof a physical uplink control channel (PUCCH), determining transmissionpower of at least one first uplink shared channel (PUSCH) to which anuplink control information (UCI) is not mapped by scaling down thetransmission power thereof among a plurality of PUSCHs on the basis ofmaximum transmission power of the terminal and the transmission power ofthe PUCCH, determining transmission power of at least one second PUSCHto which the UCI is mapped among the plurality of PUSCHs, andtransmitting the UCI and uplink (UL) data through the PUCCH, the atleast one first PUSCH, and the at least one second PUSCH. The at leastone first PUSCH and the at least one second PUSCH are allocated to aplurality of UL component carriers (CCs).

Transmission power of each uplink channel can be properly allocated whenmaximum transmission power of a user equipment is limited.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a wireless communication system.

FIG. 2 shows the structure of a radio frame in 3GPP LTE.

FIG. 3 shows an example of a resource grid of a single downlink slot.

FIG. 4 shows the structure of a downlink subframe.

FIG. 5 shows the structure of an uplink subframe.

FIG. 6 shows an example of the structure of a transmitter in an SC-FDMAsystem.

FIG. 7 shows an example of a scheme in which the subcarrier mapper mapsthe complex-valued symbols to the respective subcarriers of thefrequency domain.

FIG. 8 shows an example of the structure of a reference signaltransmitter for demodulation.

FIG. 9 shows examples of a subframe through which a reference signal istransmitted.

FIG. 10 shows an example of a transmitter using the clustered DFT-s OFDMtransmission scheme.

FIG. 11 shows another example of a transmitter using the clustered DFT-sOFDM transmission scheme.

FIG. 12 is another example of a transmitter using the clustered DFT-sOFDM transmission scheme.

FIG. 13 is an exemplary process of handling an uplink shared channel(UL-SCH) transport channel.

FIG. 14 shows an example of a physical resource element to which a datachannel and a control channel are mapped in 3GPP LTE.

FIG. 15 is another exemplary process of handling a UL-SCH transportchannel.

FIG. 16 shows an example of a transmitter and a receiver whichconstitute a carrier aggregation system.

FIG. 17 and FIG. 18 show other examples of a transmitter and a receiverwhich constitutes a carrier aggregation system.

FIG. 19 shows the proposed transmission power control method accordingto an embodiment of the present invention.

FIG. 20 is a block diagram showing wireless communication system toimplement an embodiment of the present invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following technique may be used for various wireless communicationsystems such as code division multiple access (CDMA), a frequencydivision multiple access (FDMA), time division multiple access (TDMA),orthogonal frequency division multiple access (OFDMA), singlecarrier-frequency division multiple access (SC-FDMA), and the like. TheCDMA may be implemented as a radio technology such as universalterrestrial radio access (UTRA) or CDMA2000. The TDMA may be implementedas a radio technology such as a global system for mobile communications(GSM)/general packet radio service (GPRS)/enhanced data rates for GSMevolution (EDGE). The OFDMA may be implemented by a radio technologysuch as institute of electrical and electronics engineers (IEEE) 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, E-UTRA (evolved UTRA), andthe like. IEEE 802.16m, an evolution of IEEE 802.16e, provides backwardcompatibility with a system based on IEEE 802.16e. The UTRA is part of auniversal mobile telecommunications system (UMTS). 3GPP (3rd generationpartnership project) LTE (long term evolution) is part of an evolvedUMTS (E-UMTS) using the E-UTRA, which employs the OFDMA in downlink andthe SC-FDMA in uplink. LTE-A (advanced) is an evolution of 3GPP LTE.

Hereinafter, for clarification, LTE-A will be largely described, but thetechnical concept of the present invention is not meant to be limitedthereto.

FIG. 1 shows a wireless communication system.

The wireless communication system 10 includes at least one base station(BS) 11. Respective BSs 11 provide a communication service to particulargeographical areas 15 a, 15 b, and 15 c (which are generally calledcells). Each cell may be divided into a plurality of areas (which arecalled sectors). A user equipment (UE) 12 may be fixed or mobile and maybe referred to by other names such as MS (mobile station), MT (mobileterminal), UT (user terminal), SS (subscriber station), wireless device,PDA (personal digital assistant), wireless modem, handheld device. TheBS 11 generally refers to a fixed station that communicates with the UE12 and may be called by other names such as eNB (evolved-NodeB), BTS(base transceiver system), access point (AP), etc.

In general, a UE belongs to one cell, and the cell to which a UE belongsis called a serving cell. A BS providing a communication service to theserving cell is called a serving BS. The wireless communication systemis a cellular system, so a different cell adjacent to the serving cellexists. The different cell adjacent to the serving cell is called aneighbor cell. A BS providing a communication service to the neighborcell is called a neighbor BS. The serving cell and the neighbor cell arerelatively determined based on a UE.

This technique can be used for downlink or uplink. In general, downlinkrefers to communication from the BS 11 to the UE 12, and uplink refersto communication from the UE 12 to the BS 11. In downlink, a transmittermay be part of the BS 11 and a receiver may be part of the UE 12. Inuplink, a transmitter may be part of the UE 12 and a receiver may bepart of the BS 11.

The wireless communication system may be any one of a multiple-inputmultiple-output (MIMO) system, a multiple-input single-output (MISO)system, a single-input single-output (SISO) system, and a single-inputmultiple-output (SIMO) system. The MIMO system uses a plurality oftransmission antennas and a plurality of reception antennas. The MISOsystem uses a plurality of transmission antennas and a single receptionantenna. The SISO system uses a single transmission antenna and a singlereception antenna. The SIMO system uses a single transmission antennaand a plurality of reception antennas. Hereinafter, a transmissionantenna refers to a physical or logical antenna used for transmitting asignal or a stream, and a reception antenna refers to a physical orlogical antenna used for receiving a signal or a stream.

FIG. 2 shows the structure of a radio frame in 3GPP LTE.

It may be referred to Paragraph 5 of “Technical Specification GroupRadio Access Network; Evolved Universal Terrestrial Radio Access(E-UTRA); Physical channels and modulation (Release 8)” to 3GPP (3rdgeneration partnership project) TS 36.211 V8.2.0 (2008-03). Referring toFIG. 2, the radio frame includes 10 subframes, and one subframe includestwo slots. The slots in the radio frame are numbered by #0 to #19. Atime taken for transmitting one subframe is called a transmission timeinterval (TTI). The TTI may be a scheduling unit for a datatransmission. For example, a radio frame may have a length of 10 ms, asubframe may have a length of 1 ms, and a slot may have a length of 0.5ms.

One slot includes a plurality of orthogonal frequency divisionmultiplexing (OFDM) symbols in a time domain and a plurality ofsubcarriers in a frequency domain. Since 3GPP LTE uses OFDMA indownlink, the OFDM symbols are used to express a symbol period. The OFDMsymbols may be called by other names depending on a multiple-accessscheme. For example, when a single carrier frequency division multipleaccess (SC-FDMA) is in use as an uplink multi-access scheme, the OFDMsymbols may be called SC-FDMA symbols. A resource block (RB), a resourceallocation unit, includes a plurality of continuous subcarriers in aslot. The structure of the radio frame is merely an example. Namely, thenumber of subframes included in a radio frame, the number of slotsincluded in a subframe, or the number of OFDM symbols included in a slotmay vary.

3GPP LTE defines that one slot includes seven OFDM symbols in a normalcyclic prefix (CP) and one slot includes six OFDM symbols in an extendedCP.

The wireless communication system may be divided into a frequencydivision duplex (FDD) scheme and a time division duplex (TDD) scheme.According to the FDD scheme, an uplink transmission and a downlinktransmission are made at different frequency bands. According to the TDDscheme, an uplink transmission and a downlink transmission are madeduring different periods of time at the same frequency band. A channelresponse of the TDD scheme is substantially reciprocal. This means thata downlink channel response and an uplink channel response are almostthe same in a given frequency band. Thus, the TDD-based wirelesscommunication system is advantageous in that the downlink channelresponse can be obtained from the uplink channel response. In the TDDscheme, the entire frequency band is time-divided for uplink anddownlink transmissions, so a downlink transmission by the BS and anuplink transmission by the UE can be simultaneously performed. In a TDDsystem in which an uplink transmission and a downlink transmission arediscriminated in units of subframes, the uplink transmission and thedownlink transmission are performed in different subframes.

FIG. 3 shows an example of a resource grid of a single downlink slot.

A downlink slot includes a plurality of OFDM symbols in the time domainand N_(RB) number of resource blocks (RBs) in the frequency domain. TheN_(RB) number of resource blocks included in the downlink slot isdependent upon a downlink transmission bandwidth set in a cell. Forexample, in an LTE system, N_(RB) may be any one of 60 to 110. Oneresource block includes a plurality of subcarriers in the frequencydomain. An uplink slot may have the same structure as that of thedownlink slot.

Each element on the resource grid is called a resource element. Theresource elements on the resource grid can be discriminated by a pair ofindexes (k, l) in the slot. Here, k (k=0, . . . , N_(RB)×12−1) is asubcarrier index in the frequency domain, and 1 is an OFDM symbol indexin the time domain.

Here, it is illustrated that one resource block includes 7×12 resourceelements made up of seven OFDM symbols in the time domain and twelvesubcarriers in the frequency domain, but the number of OFDM symbols andthe number of subcarriers in the resource block are not limited thereto.The number of OFDM symbols and the number of subcarriers may varydepending on the length of a cyclic prefix (CP), frequency spacing, andthe like. For example, in case of a normal CP, the number of OFDMsymbols is 7, and in case of an extended CP, the number of OFDM symbolsis 6. One of 128, 256, 512, 1024, 1536, and 2048 may be selectively usedas the number of subcarriers in one OFDM symbol.

FIG. 4 shows the structure of a downlink subframe.

A downlink subframe includes two slots in the time domain, and each ofthe slots includes seven OFDM symbols in the normal CP. First three OFDMsymbols (maximum four OFDM symbols with respect to a 1.4 MHz bandwidth)of a first slot in the subframe corresponds to a control region to whichcontrol channels are allocated, and the other remaining OFDM symbolscorrespond to a data region to which a physical downlink shared channel(PDSCH) is allocated.

The PDCCH may carry a transmission format and a resource allocation of adownlink shared channel (DL-SCH), resource allocation information of anuplink shared channel (UL-SCH), paging information on a PCH, systeminformation on a DL-SCH, a resource allocation of an higher layercontrol message such as a random access response transmitted via aPDSCH, a set of transmission power control commands with respect toindividual UEs in a certain UE group, an activation of a voice overinternet protocol (VoIP), and the like. A plurality of PDCCHs may betransmitted in the control region, and a UE can monitor a plurality ofPDCCHs. The PDCCHs are transmitted on one or an aggregation of aplurality of consecutive control channel elements (CCE). The CCE is alogical allocation unit used to provide a coding rate according to thestate of a wireless channel. The CCE corresponds to a plurality ofresource element groups. The format of the PDCCH and an available numberof bits of the PDCCH are determined according to an associative relationbetween the number of the CCEs and a coding rate provided by the CCEs.

The BS determines a PDCCH format according to a DCI to be transmitted tothe UE, and attaches a cyclic redundancy check (CRC) to the DCI. Aunique radio network temporary identifier (RNTI) is masked on the CRCaccording to the owner or the purpose of the PDCCH. In case of a PDCCHfor a particular UE, a unique identifier, e.g., a cell-RNTI (C-RNTI), ofthe UE, may be masked on the CRC. Or, in case of a PDCCH for a pagingmessage, a paging indication identifier, e.g., a paging-RNTI (P-RNTI),may be masked on the CRC. In case of a PDCCH for a system informationblock (SIB), a system information identifier, e.g., a systeminformation-RNTI (SI-RNTI), may be masked on the CRC. In order toindicate a random access response, i.e., a response to a transmission ofa random access preamble of the UE, a random access-RNTI (RA-RNTI) maybe masked on the CRC. The DCI to which the CRC is attached may betransmitted by using channel coding and rate matching.

FIG. 5 shows the structure of an uplink subframe.

An uplink subframe may be divided into a control region and a dataregion in the frequency domain. A physical uplink control channel(PUCCH) for transmitting uplink control information is allocated to thecontrol region. A physical uplink shared channel (PUCCH) fortransmitting data is allocated to the data region. If indicated by ahigher layer, the user equipment may support simultaneous transmissionof the PUCCH and the PUSCH.

The PUCCH for one UE is allocated in an RB pair. RBs belonging to the RBpair occupy different subcarriers in each of a 1^(st) slot and a 2^(nd)slot. A frequency occupied by the RBs belonging to the RB pair allocatedto the PUCCH changes at a slot boundary. This is called that the RB pairallocated to the PUCCH is frequency-hopped at a slot boundary. Since theUE transmits UL control information over time through differentsubcarriers, a frequency diversity gain can be obtained. In the figure,m is a location index indicating a logical frequency-domain location ofthe RB pair allocated to the PUCCH in the subframe.

Uplink control information transmitted on the PUCCH may include a HARQACK/NACK, a channel quality indicator (CQI) indicating the state of adownlink channel, a scheduling request (SR) which is an uplink radioresource allocation request, and the like.

The PUSCH is mapped to a uplink shared channel (UL-SCH), a transportchannel. Uplink data transmitted on the PUSCH may be a transport block,a data block for the UL-SCH transmitted during the TU. The transportblock may be user information. Or, the uplink data may be multiplexeddata. The multiplexed data may be data obtained by multiplexing thetransport block for the UL-SCH and control information. For example,control information multiplexed to data may include a CQI, a precodingmatrix indicator (PMI), an HARQ, a rank indicator (RI), or the like. Orthe uplink data may include only control information.

FIG. 6 shows an example of the structure of a transmitter in an SC-FDMAsystem.

Referring to FIG. 6, the transmitter 50 includes a discrete Fouriertransform (DFT) unit 51, a subcarrier mapper 52, an inverse fast Fouriertransform (IFFT) unit 53, and a cyclic prefix (CP) insertion unit 54.The transmitter 50 may include a scramble unit (not shown), a modulationmapper (not shown), a layer mapper (not shown), and a layer permutator(not shown), which may be placed in front of the DFT unit 51.

The DFT unit 51 outputs complex-valued symbols by performing DFT oninput symbols. For example, when Ntx symbols are input (where Ntx is anatural number), a DFT size is Ntx. The DFT unit 51 may be called atransform precoder. The subcarrier mapper 52 maps the complex-valuedsymbols to the respective subcarriers of the frequency domain. Thecomplex-valued symbols may be mapped to resource elements correspondingto a resource block allocated for data transmission. The subcarriermapper 52 may be called a resource element mapper. The IFFT unit 53outputs a baseband signal for data (that is, a time domain signal) byperforming IFFT on the input symbols. The CP insertion unit 54 copiessome of the rear part of the baseband signal for data and inserts thecopied parts into the former part of the baseband signal for data.Orthogonality may be maintained even in a multi-path channel becauseinter-symbol interference (ISI) and inter-carrier interference (ICI) areprevented through CP insertion.

FIG. 7 shows an example of a scheme in which the subcarrier mapper mapsthe complex-valued symbols to the respective subcarriers of thefrequency domain. Referring to FIG. 7( a), the subcarrier mapper mapsthe complex-valued symbols, outputted from the DFT unit, to subcarrierscontiguous to each other in the frequency domain. ‘0’ is inserted intosubcarriers to which the complex-valued symbols are not mapped. This iscalled localized mapping. In a 3GPP LTE system, a localized mappingscheme is used. Referring to FIG. 7( b), the subcarrier mapper insertsan (L-1) number of ‘0’ every two contiguous complex-valued symbols whichare outputted from the DFT unit (L is a natural number). That is, thecomplex-valued symbols outputted from the DFT unit are mapped tosubcarriers distributed at equal intervals in the frequency domain. Thisis called distributed mapping. If the subcarrier mapper uses thelocalized mapping scheme as in FIG. 7( a) or the distributed mappingscheme as in FIG. 7( b), a single carrier characteristic is maintained.

FIG. 8 shows an example of the structure of a reference signaltransmitter for demodulation.

Referring to FIG. 8, the reference signal transmitter 60 includes asubcarrier mapper 61, an IFFT unit 62, and a CP insertion unit 63.Unlike the transmitter 50 of FIG.6, in the reference signal transmitter60, a reference signal is directly generated in the frequency domainwithout passing through the DFT unit 51 and then mapped to subcarriersthrough the subcarrier mapper 61. Here, the subcarrier mapper may mapthe reference signal to the subcarriers using the localized mappingscheme of FIG. 7( a).

FIG. 9 shows examples of a subframe through which a reference signal istransmitted.

The structure of a subframe in FIG. 9( a) shows a case of a normal CP.The subframe includes a first slot and a second slot. Each of the firstslot and the second slot includes 7 OFDM symbols. The 14 OFDM symbolswithin the subframe are assigned respective symbol indices 0 to 13.Reference signals may be transmitted through the OFDM symbols having thesymbol indices 3 and 10. The reference signals may be transmitted usinga sequence. A Zadoff-Chu (ZC) sequence may be used as the referencesignal sequence. A variety of ZC sequences may be generated according toa root index and a cyclic shift value. A BS may estimate the channels ofa plurality of UEs through an orthogonal sequence or a quasi-orthogonalsequence by allocating different cyclic shift values to the UEs. Thepositions of the reference signals occupied in the two slots within thesubframe in the frequency domain may be identical with each other ordifferent from each other. In the two slots, the same reference signalsequence is used. Data may be transmitted through the remaining SC-FDMAsymbols other than the SC-FDMA symbols through which the referencesignals are transmitted. The structure of a subframe in FIG. 9( b) showsa case of an extended CP. The subframe includes a first slot and asecond slot. Each of the first slot and the second slot includes 6SC-FDMA symbols. The 12 SC-FDMA symbols within the subframe are assignedsymbol indices 0 to 11. Reference signals are transmitted through theSC-FDMA symbols having the symbol indices 2 and 8. Data is transmittedthrough the remaining SC-FDMA symbols other than the SC-FDMA symbolsthrough which the reference signals are transmitted.

Although not shown in FIG. 9, a sounding reference signal (SRS) may betransmitted through the OFDM symbols within the subframe. The SRS is areference signal for UL scheduling which is transmitted from UE to a BS.The BS estimates a UL channel through the received SRS and uses theestimated UL channel in UL scheduling.

A clustered DFT-s OFDM transmission scheme is a modification of theexisting SC-FDMA transmission scheme and is a method of dividing datasymbols, subjected to a precoder, into a plurality of subblocks,separating the subblocks, and mapping the subblocks in the frequencydomain.

FIG. 10 shows an example of a transmitter using the clustered DFT-s OFDMtransmission scheme. Referring to FIG. 10, the transmitter 70 includes aDFT unit 71, a subcarrier mapper 72, an IFFT unit 73, and a CP insertionunit 74. The transmitter 70 may further include a scramble unit (notshown), a modulation mapper (not shown), a layer mapper (not shown), anda layer permutator (not shown), which may be placed in front of the DFTunit 71.

Complex-valued symbols outputted from the DFT unit 71 are divided into Nsubblocks (N is a natural number). The N subblocks may be represented bya subblock #1, a subblock #2, . . . , a subblock #N. The subcarriermapper 72 distributes the N subblocks in the frequency domain and mapsthe N subblocks to subcarriers. The NULL may be inserted every twocontiguous subblocks. The complex-valued symbols within one subblock maybe mapped to subcarriers contiguous to each other in the frequencydomain. That is, the localized mapping scheme may be used within onesubblock.

The transmitter 70 of FIG. 10 may be used both in a single carriertransmitter or a multi-carrier transmitter. If the transmitter 70 isused in the single carrier transmitter, all the N subblocks correspondto one carrier. If the transmitter 70 is used in the multi-carriertransmitter, each of the N subblocks may correspond to one carrier.Alternatively, even if the transmitter 70 is used in the multi-carriertransmitter, a plurality of subblocks of the N subblocks may correspondto one carrier. Meanwhile, in the transmitter 70 of FIG. 10, a timedomain signal is generated through one IFFT unit 73. Accordingly, inorder for the transmitter 70 of FIG. 10 to be used in a multi-carriertransmitter, subcarrier intervals between contiguous carriers in acontiguous carrier allocation situation must be aligned.

FIG. 11 shows another example of a transmitter using the clustered DFT-sOFDM transmission scheme. Referring to FIG. 11, the transmitter 80includes a DFT unit 81, a subcarrier mapper 82, a plurality of IFFTunits 83-1, 83-2, . . . , 83-N (N is a natural number), and a CPinsertion unit 84. The transmitter 80 may further include a scrambleunit (not shown), a modulation mapper (not shown), a layer mapper (notshown), and a layer permutator (not shown), which may be placed in frontof the DFT unit 71.

IFFT is individually performed on each of N subblocks. An n^(th) IFFTunit 38-n outputs an n^(th) baseband signal (n=1, 2, . . . , N) byperforming IFFT on a subblock #n. The n^(th) baseband signal ismultiplied by an n^(th) carrier signal to produce an n^(th) radiosignal. After the N radio signals generated from the N subblocks areadded, a CP is inserted by the CP insertion unit 314. The transmitter 80of FIG. 11 may be used in a discontiguous carrier allocation situationwhere carriers allocated to the transmitter are not contiguous to eachother.

FIG. 12 is another example of a transmitter using the clustered DFT-sOFDM transmission scheme. FIG. 12 is a chunk-specific DFT-s OFDM systemperforming DFT precoding on a chunk basis. This may be called NxSC-FDMA. Referring to

FIG. 12, the transmitter 90 includes a code block division unit 91, achunk division unit 92, a plurality of channel coding units 93-1, . . ., 93-N, a plurality of modulators 94-1, . . . , 4914-N, a plurality ofDFT units 95-1, . . . , 95-N, a plurality of subcarrier mappers 96-1, .. . , 96-N, a plurality of IFFT units 97-1, . . . , 97-N, and a CPinsertion unit 98. Here, N may be the number of multiple carriers usedby a multi-carrier transmitter. Each of the channel coding units 93-1, .. . , 93-N may include a scramble unit (not shown). The modulators 94-1,. . . , 94-N may also be called modulation mappers. The transmitter 90may further include a layer mapper (not shown) and a layer permutator(not shown) which may be placed in front of the DFT units 95-1, . . . ,95-N.

The code block division unit 91 divides a transmission block into aplurality of code blocks. The chunk division unit 92 divides the codeblocks into a plurality of chunks. Here, the code block may be datatransmitted by a multi-carrier transmitter, and the chunk may be a datapiece transmitted through one of multiple carriers. The transmitter 90performs DFT on a chunk basis. The transmitter 90 may be used in adiscontiguous carrier allocation situation or a contiguous carrierallocation situation.

FIG. 13 is an exemplary process of handling an uplink shared channel(UL-SCH) transport channel. Data is delivered to a coding unit in aformat of at most one transport block for each transmission timeinterval (TTI). The process of handling the UL-SCH transport channel ofFIG. 13 is also applicable to each UL-SCH transport channel of each ULcell.

Referring to FIG. 13, in step S100, a cyclic redundancy check (CRC) isattached to a transport block. By attaching the CRC, error detection canbe supported. A size of the transport block may be denoted as A, a sizeof a parity bit may be denoted as L, and B may be defined as B=A+L.

In step S110, the CRC-attached transport block is segmented into aplurality of code blocks, and a CRC is attached to each code block. Asize of each code block may be denoted as Kr, where r is a code blocknumber.

In step S120, channel coding is performed on each code block. In thiscase, the channel coding can be performed using a turbo coding scheme.Since a coding rate of the turbo coding is ⅓, three coded streams aregenerated. Each coded stream having a code block number r has a size ofDr.

In step S130, rate matching is performed on each channel-coded codeblock. When the code block number is r, the number of rate-matched bitscan be expressed as Er.

In step S140, the respective rate-matched code blocks are concatenatedwith each other. G denotes the total number of bits for the concatenatedcode blocks. Herein, a bit used for control information transmission isexcluded from a given transport block on N_(L) transport layers. In thiscase, the control information can be multiplexed with UL-SCHtransmission.

In step S141 to step S143, channel coding is performed on the controlinformation.

The control information may include channel quality informationincluding a CQI and/or a PMI, an HARQ-ACK, an RI, etc. It is assumedhereinafter that the CQI includes the PMI. For each piece of controlinformation, a different coding rate is applied according to the numberof different coding symbols. When the control information is transmittedthrough a PUSCH, channel coding is independently performed on the CQI,the RI, and the HARQ-ACK. Although it is assumed in the presentembodiment that the CQI, the RI, and the HARQ-ACK are channel-codedrespectively in step S141, step S142, and step S143, the presentinvention is not limited thereto.

In step S150, data and control information are multiplexed. In thiscase, HARQ-ACK information exists in both of two slots of a subframe,and can be mapped to resources around a demodulation reference signal(DMRS). By multiplexing the data and the control information, the dataand the control information can be mapped to different modulationsymbols. Meanwhile, when one or more UL-SCH transport blocks aretransmitted in a subframe of a UL cell, CQI information can bemultiplexed with data on a UL-SCH transport block having a highestmodulation and coding scheme (MCS).

In step S160, channel interleaving is performed. The channelinterleaving can be performed in association with PUSCH resourcemapping. By the channel interleaving, a modulation symbol can betime-first mapped in a transmit waveform. HARQ-ACK information can bemapped to resources around a UL DMRS. RI information can be mappedaround resources used by the HARQ-ACK information.

FIG. 14 shows an example of a physical resource element to which a datachannel and a control channel are mapped in 3GPP LTE. A horizontal axisdenotes a virtual subcarrier which is an input of discrete Fouriertransform (DFT). A vertical axis denotes an SC-FDMA symbol. A referencesignal is mapped to a 4^(th) SC-FDMA symbol of each slot. Data and a CQIare mapped in a time-first manner. The data and the CQI can bemultiplexed in a serial link manner. An encoded HARQ-ACK is mapped to anSC-FDMA symbol located next to the SC-FDMA symbol to which the referencesignal is mapped. A resource used for the HARQ-ACK may be located in alast portion of a virtual subcarrier. HARQ-ACK information may exist inboth of two slots in a subframe. Irrespective of whether the HARQ-ACK istransmitted, an RI can be rate-matched next to a resource element towhich the HARQ-ACK is mapped. The maximum number of SC-FDMA symbols towhich the HARQ-ACK and the RI are mapped may be 4.

FIG. 15 is another exemplary process of handling a UL-SCH transportchannel. In step S200, a UE recognizes an RI of a UL-SCH. In step S210,the UE determines a rank of the UL-SCH to a rank of a control channel.In this case, the number of information bits of the control channel maybe extended according to the rank of the control channel. The number ofinformation bits of the control channel can be extended by using simplerepetition or a circular buffer. For example, if the information bit is[a0 a1 a2 a3] and the number of ranks is 2, the extended informationbits may be [a0 a1 a2 a3 a0 a1 a2 a3] by using the simple repetition. Bylimiting the rank of the control channel to the rank of the datachannel, a signaling overhead can be avoided. Since a DMRS is precodedby using the same precoding as that used in a data part, if the rank ofthe control channel differs from the rank of the data channel,additional signaling may be necessary for a PMI for the control channel.In this case, even if the number of effective ranks of the controlchannel is 1, the rank of the control channel can be determined to beequal to the rank of the data channel.

In step S220, the UE multiplexes the data and the control channel. Instep S230, the UE performs a channel interleaving process. In step S240,the UE modulates the data and the control channel by using a modulationscheme such as quadrature phase shift keying (QPSK), 16 quadratureamplitude modulation (QAM), 64 QAM, or the like according to an MCStable. The modulation scheme of step S240 can also be performed in anysteps of the aforementioned process of handling the UL-SCH transportchannel of FIG. 15. Subsequently, DFT, MIMO precoding, resource elementmapping, etc., can be performed.

When assuming two codewords, channel coding is performed for eachcodeword, and rate matching is performed according to the given MCStable. An encoded information bit can be scrambled in a cell-specific,UE-specific, or codeword-specific manner. Subsequently, the codeword canbe mapped to a layer. In this case, layer shifting or layer permutationcan be performed.

3GPP LTE-A supports a carrier aggregation (CA) system. The CA system mayrefer to 3GPP TR 36.815 V9.0.0 (2010-03).

A carrier aggregation (CA) system implies a system that configures awideband by aggregating one or more carriers having a bandwidth smallerthan that of a target wideband when the wireless communication systemintends to support the wideband. The CA system can also be referred toas other terms such as a bandwidth aggregation system, or the like. Thecarrier aggregation system can be divided into a contiguous carrieraggregation system in which carriers are contiguous to each other and anon-contiguous carrier aggregation system in which carriers areseparated from each other. In the contiguous carrier aggregation system,a frequency spacing may exist between respective carriers. A carrierwhich is a target when aggregating one or more carriers can directly usea bandwidth that is used in the legacy system in order to providebackward compatibility with the legacy system. For example, a 3^(rd)generation partnership project (3GPP) long-term evolution (LTE) systemcan support a bandwidth of 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20MHz, and a 3GPP LTE-A system can configure a wideband of 20 MHz orhigher by using only the bandwidth of the 3GPP LTE system.Alternatively, the wideband can be configured by defining a newbandwidth without having to directly use the bandwidth of the legacysystem.

In the carrier aggregation system, a user equipment (UE) can transmit orreceive one or multiple carriers simultaneously according to capacity.An LTE-A UE can transmit or receive the multiple carrierssimultaneously. An LTE Rel-8 UE can transmit or receive only one carrierwhen each of carriers constituting the carrier aggregation system iscompatible with an LTE Rel-8 system. Therefore, when the number ofcarriers used in an uplink (UL) is equal to the number of carriers usedin a downlink (DL), it is necessary to configure such that all componentcarriers (CCs) are compatible with the LTE Rel-8 system.

In order to efficiently use multiple carriers, the multiple carriers canbe managed by media access control (MAC). In order to transmit/receivethe multiple carriers, both a transmitter and a receiver must be able totransmit/receive the multiple carriers.

FIG. 16 shows an example of a transmitter and a receiver whichconstitute a carrier aggregation system.

In the transmitter of FIG. 16( a), one MAC transmits and receives databy managing and operating all of n carriers. This is also applied to thereceiver of FIG. 16( b). From the perspective of the receiver, onetransport block and one HARQ entity may exist per CC. A UE can bescheduled simultaneously for multiple carriers. The carrier aggregationsystem of FIG. 16 can apply both to a contiguous carrier aggregationsystem and a non-contiguous carrier aggregation system. The respectivecarriers managed by one MAC do not have to be contiguous to each other,which results in flexibility in terms of resource management.

FIG. 17 and FIG. 18 show other examples of a transmitter and a receiverwhich constitutes a carrier aggregation system.

In the transmitter of FIG. 17( a) and the receiver of FIG. 17( b), oneMAC manages only one carrier. That is, the MAC and the carrier are 1:1mapped. In the transmitter of FIG. 18( a) and the receiver of FIG. 18(b), a MAC and a carrier are 1:1 mapped for some carriers, and regardingthe remaining carriers, one MAC controls multiple carriers. That is,various combinations are possible based on a mapping relation betweenthe MAC and the carrier.

The carrier aggregation system of FIG. 16 to FIG. 18 includes ncarriers. The respective carriers may be contiguous to each other or maybe separated from each other. The carrier aggregation system can applyboth to a UL and a DL. In a TDD system, each carrier is configured to beable to perform UL transmission and DL transmission. In an FDD system,multiple carriers can be used by dividing them for a UL and a DL. In atypical TDD system, the number of CCs used in the UL is equal to thatused in the DL, and each carrier has the same bandwidth. The FDD systemcan configure an asymmetric carrier aggregation system by allowing thenumber of carriers and the bandwidth to be different between the UL andthe DL.

Meanwhile, the concept of a cell can be applied in the LTE-A system. Thecell is an entity configured by combining at least one unit of DLresources and selectively included UL resources from the perspective ofa UE. That is, one cell must include at least one unit of DL resources,but may not include UL resources. The one unit of DL resources may beone DL CC. A linkage between a carrier frequency of a DL resource and acarrier frequency of a UL resource can be indicated by an SIB2transmitted using the DL resource. Although a component carrier (CC)will be taken as an example in the following descriptions of the presentinvention, it is apparent that the CC can be replaced with a cell.

A cell type can be classified according to an allocation method. First,the number of cells allocated to an entire system may be fixed. Forexample, the number of cells allocated to the entire system may be 8.All or some of the cells allocated to the entire system may be allocatedby radio resource control (RRC) signaling of a higher layer. The cellallocated by the RRC signaling is called a configured cell. That is, theconfigured cell may imply a cell allocated to be usably by the systemamong the cells allocated to the entire system. All or some of theconfigured cells may be allocated by media access control (MAC)signaling. The cell allocated by the MAC signaling can be called anactivated cell. Among the configured cells, the remaining cells otherthan the activated cell can be called a deactivated cell. All or some ofthe activated cells are allocated to the UE by using L1/L2 signaling.The cell allocated by using the L1/L2 signaling can be called ascheduled cell. The scheduling cell can receive data through a PDSCH byusing a DL resource in a cell, and can transmit data through a PUSCH byusing a UL resource.

Hereinafter, a transmission power control method proposed in the presentinvention will be described.

A periodic uplink control information (UCI) and an aperiodic channelquality indicator (CQI) can be transmitted through a plurality of ULCCs. The periodic UCI can be transmitted through a PUCCH or can betransmitted by being piggybacked on a PUSCH. By using the piggyback-typetransmission, the UCI can be transmitted through the PUSCH withouthaving to be transmitted through the PUCCH. Accordingly, multiplechannels can be prevented from simultaneous transmission, and thus it ispossible to prevent an increased peak-to-average power ratio(PAPR)/cubic metric (CM) problem or an inter-modulation distortion (IMD)problem. Meanwhile, total transmission power of the UE may be limited toa specific level, and if the periodic UCI and the aperiodic CQI aretransmitted through a PUSCH or PUCCH allocated to a plurality of UL CCs,transmission power for each UL channel may also be limited. In thiscase, how to control the transmission power of each UL channel, that is,a method of setting a priority when allocating the transmission power toeach UL channel, can be proposed. Hereinafter, the proposed transmissionpower control method will be described according to an embodiment of thepresent invention. It is assumed hereinafter that the UCI includes boththe periodic UCI and the aperiodic CQI.

First, a PUSCH transmitting the UCI may be prioritized over a PUSCH nottransmitting the UCI. In addition, a PUCCH may be prioritized over thePUSCH transmitting the UCI. Transmission power of a PUSCH on which theUCI is not piggybacked may be first scaled down, and occasionally,transmission power of the PUSCH on which the UCI is not piggybacked maybe zero. A priority of the PUCCH, the PUSCH transmitting the UCI and thePUSCH not transmitting the UCI may be applied irrespective of whetherusing the same UL CC or different UL CCs.

In addition, the priority is also applicable to a case in which thePUCCH and the PUSCH transmitting the UCI are transmitted simultaneously.

If a sum of transmission powers of respective UL channels including thePUCCH and the PUSCH exceeds maximum transmission power of the UE, the UEcan scale down the transmission power of each PUSCH to satisfy Equation1 below.

$\begin{matrix}{{\sum\limits_{c}{w_{c} \cdot {P_{PUSCHc}(i)}}} \leq {P_{CMAX} - {P_{PUCCH}(i)}}} & {\langle{{Equation}\mspace{14mu} 1}\rangle}\end{matrix}$

In Equation 1, w_(c) is a scaling factor for transmission power of aPUSCH in a UL CC having an index c. P_(PUSCHc)(i) is transmission powerof each PUSCH, P_(CMAX) is maximum transmission power of a UE, andP_(PUCCH)(i) is transmission power of a PUCCH. That is, the scalingfactor w_(c) can be applied to the transmission power of the PUSCH sothat a sum of transmission powers of the respective PUSCHs does notexceed a value obtained by subtracting the transmission power of thePUSCH from the maximum transmission power of the UE according toEquation 1. The scaling factor can be applied to the transmission powerof the PUSCH on which the UCI is not transmitted.

Quality of service (QoS) of data transmitted through the PUSCH of a ULCC may depend on mapping to a physical resource of a logical channel.Scaling of transmission power may depend on a current power controlstatus of each UL CC that can be known only to the UE. In addition, amaximum tolerable power difference between channels can be considered.Such aspects can be considered in the implementation of the UE.Meanwhile, there is a need to minimize a case in which transmissionpower of a UL channel is decreased due to an influence of a scalingfactor according to a suitable scheduler and a power control scheme. Inparticular, there is a need to minimize the influence of the scalingfactor w_(c) applied to the transmission power of the PUSCH whenperforming HARQ. For this, equal scaling, TF-dependent scaling, etc.,can be considered when determining the scaling factor w_(c).

In addition, the proposed transmission power control method is alsoapplicable to a case in which a UCI is transmitted through one or morePUSCHs on a given UL subframe. That is, this is a case in which aplurality of PUSCHs are allocated respectively to a plurality of UL CCsin one given UL subframe, and a periodic UCI, an aperiodic CQI, or and ajointly encoded periodic UCI and aperiodic CQI is transmitted throughthe plurality of PUSCHs. If the number of PUSCHs for transmitting theUCI is one, as described above, transmission power which remains aftersubtracting the transmission power of the PUCCH from the maximumtransmission power P_(CMAX) of the UE can be allocated as thetransmission power of the PUSCH. In this case, the transmission power ofthe PUSCH transmitting the UCI may be allocated more preferentially thanthe transmission power of the PUSCH not transmitting the UCI, and thescaling factor w_(c) is applicable to the transmission power of thePUSCH.

A similar method may also be applicable to a case in which the UCI istransmitted through a plurality of PUSCHs. The transmission power whichremains after subtracting the transmission power of the PUSCH from themaximum transmission power P_(CMAX) of the UE can be allocated as thetransmission power of the PUSCH. Scaling down of transmission power canbe first performed on the PUSCH not transmitting the UCI, and theremaining transmission power can be allocated by being distributed to aplurality of PUSCHs transmitting the UCL Transmission power of eachPUSCH can be evenly distributed when the transmission power isdistributed to the plurality of PUSCHs transmitting the UCI, ortransmission power can be distributed by setting a priority for theplurality of PUSCHs transmitting the UCI. For example, a PUSCH allocatedto a UL primary CC (PCC) may be prioritized over a PUSCH allocated toanother UL CC. This is because a scheduling request (SR) signal and anACK/NACK signal which are relatively important among periodic UCIs aretransmitted on the UL PCC. That is, scaling down of transmission poweris first performed on a PUSCH allocated not to the UL PCC but to anotherUL CC, and the remaining transmission power can be allocated to a PUSCHallocated to the UL PCC.

If the PUSCH is not allocated to the UL PCC, a priority of thetransmission power of the plurality of PUSCHs can be determined by usingvarious methods. For example, a priority of a PUSCH to whichtransmission power is allocated can be dynamically set through PDCCHsignaling. The priority of the PUSCH can be set semi-statically throughhigher layer signaling. Alternatively, the priority of the plurality ofPUSCHs can be implicitly set without additional signaling. In this case,the priority can be set in a lowest or highest order of a physical CCindex or a logical CC index of a UL CCs to which the PUSCH fortransmitting the UCI is allocated. Alternatively, the priority can beset according to a size of a transmission block (TB). For example, thepriority can be set in a descending order of a size of scheduled ULresources of the UL CC or in a descending order of a modulation andcoding scheme (MCS) level of the UL CC. Alternatively, the priority canbe set on the basis of quality of service (QoS) of UL CCs to which thePUSCH for transmitting the UCI is allocated. In this case, the QoS forthe UL CC can be reported by a BS.

If a periodic UCI and an aperiodic CQI are transmitted simultaneouslythrough a plurality of UL CCs in one subframe additionally given,transmission power of a PUSCH for transmitting the aperiodic CQI may beprioritized over transmission power of a PUSCH for transmitting theperiodic UCI. That is, transmission power of the PUSCH for transmittingthe periodic UCI may be first scaled down. This is because a signal fortriggering an aperiodic CQI is transmitted through a UL grant, and anaperiodic CQI for a corresponding DL CC is more important than theperiodically transmitted UCI from the perspective of a network.

FIG. 19 shows the proposed transmission power control method accordingto an embodiment of the present invention.

In step S300, a UE determines transmission power of a PUCCH. In stepS310, the UE determines transmission power of at least one first PUSCHto which a UCI is not mapped among a plurality of PUSCHs by scaling downthe transmission power on the basis of maximum transmission power andthe transmission power of the PUCCH. In this case, Equation 1 can beapplied. In step S320, the UE determines transmission power of at leastone second PUSCH among the plurality of PUSCHs. In step S330, the UEtransmits the UCI and UL data through the PUCCH, the at least one firstPUSCH, and the at least one second PUSCH. The at least one first PUSCHand the at least one second PUSCH are allocated to a plurality of ULCCs, and transmission power of each UL channel can be determinedaccording to the aforementioned various transmission power controlmethods.

FIG. 20 is a block diagram showing wireless communication system toimplement an embodiment of the present invention.

ABS 800 may include a processor 810, a memory 820 and a radio frequency(RF) unit 830. The processor 810 may be configured to implement proposedfunctions, procedures and/or methods described in this description.Layers of the radio interface protocol may be implemented in theprocessor 810. The memory 820 is operatively coupled with the processor810 and stores a variety of information to operate the processor 810.The RF unit 830 is operatively coupled with the processor 810, andtransmits and/or receives a radio signal.

A UE 900 may include a processor 910, a memory 920 and a RF unit 930.The processor 910 may be configured to implement proposed functions,procedures and/or methods described in this description. Layers of theradio interface protocol may be implemented in the processor 910. Thememory 920 is operatively coupled with the processor 910 and stores avariety of information to operate the processor 910. The RF unit 930 isoperatively coupled with the processor 910, and transmits and/orreceives a radio signal.

The processors 810, 910 may include application-specific integratedcircuit (ASIC), other chipset, logic circuit and/or data processingdevice. The memories 820, 920 may include read-only memory (ROM), randomaccess memory (RAM), flash memory, memory card, storage medium and/orother storage device. The RF units 830, 930 may include basebandcircuitry to process radio frequency signals. When the embodiments areimplemented in software, the techniques described herein can beimplemented with modules (e.g., procedures, functions, and so on) thatperform the functions described herein. The modules can be stored inmemories 820, 920 and executed by processors 810, 910. The memories 820,920 can be implemented within the processors 810, 910 or external to theprocessors 810, 910 in which case those can be communicatively coupledto the processors 810, 910 via various means as is known in the art.

In view of the exemplary systems described herein, methodologies thatmay be implemented in accordance with the disclosed subject matter havebeen described with reference to several flow diagrams. While forpurposed of simplicity, the methodologies are shown and described as aseries of steps or blocks, it is to be understood and appreciated thatthe claimed subject matter is not limited by the order of the steps orblocks, as some steps may occur in different orders or concurrently withother steps from what is depicted and described herein. Moreover, oneskilled in the art would understand that the steps illustrated in theflow diagram are not exclusive and other steps may be included or one ormore of the steps in the example flow diagram may be deleted withoutaffecting the scope and spirit of the present disclosure.

What has been described above includes examples of the various aspects.It is, of course, not possible to describe every conceivable combinationof components or methodologies for purposes of describing the variousaspects, but one of ordinary skill in the art may recognize that manyfurther combinations and permutations are possible. Accordingly, thesubject specification is intended to embrace all such alternations,modifications and variations that fall within the spirit and scope ofthe appended claims.

What is claimed is:
 1. A method of controlling transmission power by aterminal in a wireless communication system, the method comprising:determining transmission power of a physical uplink control channel(PUCCH); determining transmission power of at least one first uplinkshared channel (PUSCH) to which an uplink control information (UCI) isnot mapped by scaling down the transmission power thereof among aplurality of PUSCHs on the basis of maximum transmission power of theterminal and the transmission power of the PUCCH; determiningtransmission power of at least one second PUSCH to which the UCI ismapped among the plurality of PUSCHs; and transmitting the UCI anduplink (UL) data through the PUCCH, the at least one first PUSCH, andthe at least one second PUSCH, wherein the at least one first PUSCH andthe at least one second PUSCH are allocated to a plurality of ULcomponent carriers (CCs).
 2. The method of claim 1, wherein thetransmission power of the at least one first PUSCH is determined bybeing scaled down to satisfy the equation of:${{\sum\limits_{c}{w_{c} \cdot {P_{PUSCHc}(i)}}} \leq {P_{CMAX} - {P_{PUCCH}(i)}}},$where w_(c) is a scaling factor for scaling down the transmission powerof the at least one first PUSCH, c is an index of a UL CC, P_(PUSCHC)(i)is the transmission power of the at least one first PUSCH, P_(CMAX) isthe maximum transmission power of the terminal; and P_(PUCCH)(i) is thetransmission power of the PUCCH.
 3. The method of claim 1, wherein theUCI is any one of a periodic UCI, an aperiodic channel quality indicator(CQI), and a jointly encoded periodic UCI and aperiodic CQI.
 4. Themethod of claim 1, wherein the transmission power of the at least onesecond PUSCH is evenly distributed to the at least one second PUSCH. 5.The method of claim 1, wherein the transmission power of the at leastone second PUSCH is allocated to the at least one second PUSCH on thebasis of a pre-set priority.
 6. The method of claim 5, wherein thetransmission power of the second PUSCH allocated to a UL primary CC(PCC) is preferentially allocated among the at least one second PUSCH.7. The method of claim 5, wherein the priority is set explicitly byphysical downlink control channel (PDCCH) signaling or radio resourcecontrol (RRC) signaling.
 8. The method of claim 5, wherein the priorityis set implicitly on the basis of a size of a transmission block (TB) oran index of a plurality of UL CCs to which the at least one second PUSCHis allocated.
 9. The method of claim 5, wherein the transmission powerof the second PUSCH to which an aperiodic CQI is mapped ispreferentially allocated among the at least one second PUSCH.
 10. Aterminal in a wireless communication system, the terminal comprising: aradio frequency (RF) unit for transmitting or receiving a radio signal;and a processor coupled to the RF unit, wherein the processor isconfigured for: determining transmission power of a physical uplinkcontrol channel (PUCCH); determining transmission power of at least onefirst uplink shared channel (PUSCH) to which an uplink controlinformation (UCI) is not mapped by scaling down the transmission powerthereof among a plurality of PUSCHs on the basis of maximum transmissionpower of the terminal and the transmission power of the PUCCH;determining transmission power of at least one second PUSCH to which theUCI is mapped among the plurality of PUSCHs; and transmitting the UCIand uplink (UL) data through the PUCCH, the at least one first PUSCH,and the at least one second PUSCH, wherein the at least one first PUSCHand the at least one second PUSCH are allocated to a plurality of ULcomponent carriers (CCs).
 11. The terminal of claim 10, wherein thetransmission power of the at least one first PUSCH is determined bybeing scaled down to satisfy the equation of:${{\sum\limits_{c}{w_{c} \cdot {P_{PUSCHc}(i)}}} \leq {P_{CMAX} - {P_{PUCCH}(i)}}},$where w_(c) is a scaling factor for scaling down the transmission powerof the at least one first PUSCH, c is an index of a UL CC, P_(PUSCHC)(i)is the transmission power of the at least one first PUSCH, P_(CMAX) isthe maximum transmission power of the terminal, and P_(PUCCH)(i) is thetransmission power of the PUCCH.
 12. The terminal of claim 10, whereinthe UCI is any one of a periodic UCI, an aperiodic channel qualityindicator (CQI), and a jointly encoded periodic UCI and aperiodic CQI.13. The terminal of claim 10, wherein the transmission power of the atleast one second PUSCH is evenly distributed to the at least one secondPUSCH.
 14. The terminal of claim 10, wherein the transmission power ofthe at least one second PUSCH is allocated to the at least one secondPUSCH on the basis of a pre-set priority.